Access to Astronomical Catalogues

← Click to display the menu
J/A+A/486/9         Redshifts in z∼0.25 clusters          (Verdugo+, 2008)

The galaxy populations from the centers to the infall regions in z∼0.25 clusters. Verdugo M., Ziegler B.L., Gerken B. <Astron. Astrophys. 486, 9 (2008)> =2008A&A...486....9V
ADC_Keywords: Clusters, galaxy ; Redshifts ; Galaxies, photometry ; Equivalent widths Keywords: galaxies: general - galaxies: evolution - galaxies: fundamental parameters - galaxies: clusters: general Abstract: We investigate the relation between star-formation activity and environment in six intermediate redshift clusters (z∼0.25) out to large clustercentric distances (∼4Rvir). For that, we conducted a panoramic spectroscopic campaign with MOSCA at the Calar Alto observatory. We acquired spectra of more than 500 objects. Approximately 150 of these spectra were of galaxies that are members of the clusters. Other ∼150 are field galaxies or galaxies belonging to groups, serendipitously found during the investigation. The rest of the spectra did not met the quality criteria or were stars. The wavelength range allows us to quantify the star formation activity by using the [OII] and the Hα lines. This activity is examined in terms of the large-scale environment expressed by the clustercentric distance of the galaxies as well as on local scales given by the spatial galaxy densities. The suppression of the star-formation activity is observed at large clustercentric distances and low projected densities. Galaxies with current star-formation show similar activity, regardless of the environment, Therefore, the decline of the star-formation activity inside the investigated clusters is driven mainly by the significant change in the fraction of active versus passive populations. This suggests that the suppression of the star-formation activity occurs on short timescales. We also detect a significant population of red star-forming galaxies whose colors are consistent with the red-sequence of passive galaxies. They appear to be in an intermediate evolutionary stage between active and passive types. Description: We present measurements for all objects for which we were able to derive secure redshifts. This includes galaxies belonging to the six aforementioned clusters, four serendipitously found groups and the general field (see the paper and below). For each object, table3.dat provides the identification code, membership, right ascension and declination (J2000.0); redshift, I-band magnitude and V-I color from Gilbank et al. (2004MNRAS.348..551G); B and R-band absolute magnitude derived with k-correct (Blanton and Roweis, 2007AJ....133..734B); stellar mass also derived using k-correct and the equivalent widths of the [OII] and the Hα emission lines and associated errors. Objects are sorted by membership to facilitate any specific search. The clusters studied are the following: VMF194 or RX J1729.0+7440; XDCS220, short for XDCS cmJ172333+744410; VMF131 or RX J1309.9+3222; VMF132 or RX J1313.2+3229; VMF73 or RX J0943.5+1640; VMF74 or RX J0943.7+1644; Galaxies belonging to the groups candidates are tagged with a group number which corresponds to one of the following identifications: group1 is r220_1J 172604+742830; group2 is r220_2J 172518+742844; group3 is r220_3J 172958+744204; group4 is r265_1J 131030+322840. Galaxies without any identifiable membership are tagged as belonging to the field. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 105 286 Individual data for 286 galaxies at intermediate redshifts
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 9 A9 --- [VZG2008] Galaxy identification code (1) 11- 17 A7 --- Memb Galaxy membership (2) 19- 20 I2 h RAh Right ascension (J2000.0) 22- 23 I2 min RAm Right ascension (J2000.0) 25- 29 F5.2 s RAs Right ascension (J2000.0) 31 A1 --- DE- Declination sign (J2000.0) 32- 33 I2 deg DEd Declination (J2000.0) 35- 36 I2 arcmin DEm Declination (J2000.0) 38- 41 F4.1 arcsec DEs Declination (J2000.0) 43- 49 F7.5 --- z Spectroscopic Redshift 51- 55 F5.2 mag Icmag Cousins I-band apparent magnitude (3) 57- 61 F5.3 mag V-Ic Johnson-Cousins V-I color index (3) 63- 68 F6.2 mag BMAG B-band absolute magnitude (4) 70- 75 F6.2 mag RMAG V-band absolute magnitude (4) 77- 81 F5.2 [solMass] log(M) logarithm of the Stellar Mass (4) 83- 88 F6.2 0.1nm EW(OII) ? Equivalent width of [OII] emission line 90- 93 F4.2 0.1nm e_EW(OII) ? Error in EW(OII) 95-100 F6.2 0.1nm EW(Ha) ? Equivalent width of Hα emission line 102-105 F4.2 0.1nm e_EW(Ha) ? Error in EW(Ha)
Note (1): All galaxies with identification codes beginning with 'r' are original of this work (r22NN_NNA, r26NN_NNA and r28NN_NNA). The prefixes r22, r26 and r28 correspond to the fields R220, R265 and R285 respectively. The following numbers are mask and slit number. Galaxies with a prefix 'ba' (ba_NN) come from Balogh et al., 2002ApJ...566..123B. Galaxy with a prefix 'xdc' (xdc29_04) is from Gilbank et al., 2004MNRAS.348..551G. Note (2): Galaxy membership as follows: field = field galaxy group1 = group candidate r220_1J 172604+742830 group2 = group candidate r220_2J 172518+742844 group3 = group candidate r220_3J 172958+744204 group4 = r265_1J 131030+322840 vmf131 = VMF131 or RX J1309.9+3222 cluster vmf132 = VMF132 or RX J1313.2+3229 cluster vmf194 = VMF194 or RX J1729.0+7440 cluster vmf73 = VMF73 or RX J0943.5+1640 cluster vmf74 = VMF74 or RX J0943.7+1644 cluster xdcs220 = XDCS220, short for XDCS cmJ172333.0+744410 cluster Note (3): The apparent magnitudes are from the project of Gilbank et al., 2004MNRAS.348..551G Note (4): The absolute magnitudes and stellar masses were calculated for a cosmology H0=70km/s/Mpc, ΩΛ=0.7 and Ωmatter=0.3.
Acknowledgements: Miguel Verdugo, mverdugo(at)
(End) Miguel Verdugo [IAG, Germany], Patricia Vannier [CDS] 21-Apr-2008
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service